Seat spring assembly utilizing auxiliary coil spring



Dec. 12, 1967 w. v. SLOMINSKI 3,357,695

} SEAT SPRING ASSEMBLY UTILIZING AUXILIARY COIL SPRING Filed April 15, 1966 2 Sheets-Sheet 3 WALTER V. SLOMINSKI 1967 w. v. SLOMINSKI 3,

SEAT SPRING ASSEMBLY UTILIZING AUXILIARY COIL SPRING Filed April 15, 1966 2 Sheets-Sheet WALTER V. SLOMINSKI 1 4 a!) ATTRNEYS INVENT OR United States Patent Office 3,357,695 Patented Dec. 12, 1967 3,357,645 SEAT SPRING ASSEMBLY UTILIZING AUXILIARY COIL SPRING Walter V. Slorninski, Lexington, Ky., assignor to Hoover Ball and Bearing Company, Saline, Mich., a corporation of Michigan Filed Apr. 15, 1966, Ser. No. 542,829 6 Claims. (Cl. 262-410) ABSTRACT OF THE DISCLOSURE A spring assembly for seats in which a longitudinally extending spring strip is assembled with a frame mounted coil spring unit that engages the spring strip so that coils in the coil spring unit yieldably resist seating loads on the spring strip.

in an axial direction. In more recent years, seating structures have utilized the well known spring strips, formed of sinuous or formed wire, so that in general, these spring strips have tended to replace the coil springs previously commonly used. Various proble mshave been encountered in the use of these spring strips, such as the problem of adapting a single spring strip design to different seating structures in which the spring requirements are different because of the different designs of the seating structures. Also, the spring strips tend to bottom, namely, reach a limit of deflection at which they no longer impart a feeling of resilient support to the seat occupant.

Various spring strip configurations have been used in the past, without complete success, in overcoming these problems. It is an-object of this invention, therefore, to provide an improved seat spring assembly in which a spring strip is combined With a coil spring unit in a manner such that the stiffness of the spring assembly and the mounting thereof is readily adaptable to various seat structures having different spring requirements, and so that the spring assembly provides for a buoyancy and depth of deflection feeling to the seat occupant throughout the full range of seat deflections. I

A further object of this invention is to provide an improved spring assembly for seating structures which is capable of standardized manufacture, easy assembly, and ready insta lation on different seating structures.

Further objects, features and advantages of this invention will become apparent from a consideration of'the following description, the appended claims, and the accompanying drawing in which:

FIGURE 1 is a fragmentary plan view of a seating structure frame provided with a plurality of the spring assemblies of this invention;

FIGURE 2 is a foreshortened transverse sectional view of the structure shown in FIG. 1, as seen from substantially the line 2-2 in FIG. 1; and

FIGURES 3-5, inclusive, are fragmentary transverse sectional views, like FIG. 2, illustrating three modified forms of the spring assembly of this invention.

With reference to the drawing, a plurality of seat spring assemblies of this invention, indicated generally at 10, areillustrated in FIG. I mounted on a seat frame 12 having a rear frame rail 14, afront frame rail 16, and side rails 18 (only one of which is shown) which connect the front and rear frame rails 14 and 16. The spring assembly consists of a longitudinally extending spring strip 20, illustrated as being of sinuous wire but which can also be made of formed wire, attached in any suitable manner at its front end to the front frame rail '16, and a coil spring unit 22 which supports the rear end of the spring strip 20 and is mounted on the rear frame rail The spring strip 20 can be of any configuration between its front and rear ends that is necessary to accomplish whatever design and feel requirements are involved in the particular seating structure to which the spring assembly 10 is applied. At its rear end, the spring strip 20 terminates in a transversely extending torsion bar or section 24, and is illustrated as having additional torsion bars 26 and 28 located adjacent the section 24.

The coil spring unit 22 consists of a single length of wire which is shaped intermediate its ends so as to form a coil spring 30 having a plurality of spaced coils 32 extended about an axis 35 which extends transversely of the spring strip 20. The single length of Wire from which the coil spring unit 22 is formed has one end section 34 which is formed integral with the endmost coil 32 at one end of the coil spring 30. The wire section 34 is shaped to form a pair of substantially parallel legs 36 and 38, with the leg 38 constituting a prong, and with the legs 36 and 38 being connected by a connecting section 40 which is substantially perpendicular to the legs 36 and 38. In the FIG. 2 form of the invention, the mounting section 34 is above the. coil spring 30 and is of generally inverted U-shaped, the distance between the legs 36 and 38 being such that when the leg 36 is pronged-into an opening 42 .in the rear frame rail 14, the leg 36 is disposed adjacent the front side of the rail 14 so as to maintain the coil spring unit 22 in a substantially fixed position on the rail 14.

The wire forming the coil spring unit 22 ,has another end portion 44 which is formed integral with thecoil 32 at the opposite end of the coil spring 30 and which constitutes an arm that extends longitudinally of the spring strip 20. In the illustrated form of the invention, the arm 44 is formed intermediate its ends with a torsion bar 46 which is substantially parallel to and in engagement with the underside of the spring strip torsion bar 26. Thearm respect to the longitudinal axis of the spring strip 20 and is adjustable as to length to vary the effect of the coil spring unit 22 on the deflection and resistancev to deflection of the spring strip 20. In the illustrated form of the invention the portion 48 is of a length to engage the underside of the torsion bar 28.

In the assembly of the spring strip 20 and the coil spring unit 22, assume that the coil spring unit 22 is mounted on the frame rail 14, as shown in FIG..2, prior to assembly of the spring strip 20' therewith. When the coil spring unit 22 is so mounted, the coil spring 30 moves the arm 44 to the broken line position shown in FIG. 2. To assemble the spring strip 20 with the coil spring unit'22, it is necessary to move the arm 44 in a counterclockwise direction as viewed in FIG. 2 to the solid line position shown for the arm 44. Such movement of the arm 44 winds up the coil 30 so as to tighten the coils 32. As shown inFIG. l, the coils 32 are spaced apart even in the solid line position of the arm 44 so as to allow for this winding up. As a result, the coil spring 30 continually exerts on the arm 44 a force tending to move the arm 44 upwardly.

most torsion bar at the rear end of the spring strip 20 in the illustrated embodiment of the invention, is extended axially through the coil spring 30, with the arm 44 in engagement with the underside of the spring strip 20. As a result, when the spring strip 20 is subjected to a seating load, namely, a downwardly directed load, such as indicated by the arrow F in FIG. 2, the transverse spring strip section 24 is engaged at its top side with the inner sides of the coils 32 at the top of the coil spring 30, and the load F is resisted by the upwardly directed force applied to the spring strip 20 by the arm 44. As the spring strip 20 is progressively loaded so as to deflect it in a downward direction, the arm 44 is move-d in a counterclockwise direction as viewed in FIG. 2 to further wind up the spring 30 and tighten the coils 32. Consequently, the magnitude of the resisting force applied to the strip 20 by the arm 44 is progressively increased during deflection of the strip 20. This action of the coil spring unit 22 on the spring strip 20 provides for a buoyancy and depth of deflection feeling to the seat occupant throughout the full range of deflection of the spring assembly 10. In other words, when the seating structure in which the spring assemblies are mounted is fully occupied, there is still bounce left in the spring assemblies 10', thereby providing increased occupant comfort.

It can thus be seen that when the spring strip and the coil spring unit 22 are assembled and mounted on the frame 12, the coil spring is effectively preloaded to impart additional resistance to deflection to the assembly 10. It is to be understood that the strip 20 and the coil spring unit 22 can be preassembled and subsequently mounted on the frame 12, the above description wherein the unit 22 is first mounted on the rail 14 being for the purpose of more clearly describing the action of the unit 22. The extent of preloading of the coil spring 30 can be adjusted during manufacture of the coil spring unit 22, and the length of the arm 44 can also be adjusted to vary the action of the assembly 10. The greater the length of the arm 44, the stiffer the spring strip 20, and in addtion, a torsion bar 26 or 28 in the spring strip 20 that is engaged by the arm 44 has its springing action reduced. Consequently, the shape of the spring strip 20 and the length and shape of the arm 44 are adjustable to meet particular seating requirements.

A modified form of the spring assembly of this invention, indicated generally at 10a, is shown in FIG. 3. The assembly 10a is identical in all respects to the assembly 10 described above except that in the assembly 10a the leg 36a in the mounting section 34a in the coil spring unit 22a is shortened relative to the leg 36 in the unit 22. The result of this modification is a raising of the coil spring unit 22a on the frame 12 which is desirable in some seating structures.

In FIG. 4 another modified form of the spring assembly of this invention, indicated generally at 10b, is illustrated in which the coil spring unit 22b is suspended from and located rearwardly of the rear frame rail 14. The mounting section 34b for the coil spring unit 22b is for this reason of a somewhat different shape than the mounting section 34 for the coil spring unit 22, and is positioned forwardly, instead of rearwardly, of the coil spring 30b. The mounting section 3412 is formed integral with one of the end coils in the coil spring 3012 in the unit 22b and is provided with substantially parallel legs 50- and 52, the leg 52 constituting a prong which is pronged into a suitable opening in the frame rail 14. A connecting section 54 between the legs 50 and 52 is of a length to space the leg 50 slightly rearwardly of the rear side of the frame rail 14 so as to avoid rubbing contact therewith. As shown in FIG. 4, in the unstressed condition of the coil spring 30b, the arm 44b would assume the broken line position so that when the coil spring unit 22b is assembled with the spring strip 20b, which is also of a somewhat different configuration than the spring strip 20 to extend it below the rear frame rail 14, the coil spring 30b is preloaded.

In all other respects, the spring strip 20b and the coil spring unit 22b and their assembly are identical to that described above in connection with the spring assembly 10.

Still another modified form of the spring assembly of this invention is indicated generally at 10c in FIG. 5 in which the coil spring unit 220 is shaped to position the coil spring 30c above the rear frame rail 14. The unit 220 is shaped to provide a mounting section 340 in which the legs 56 and 58 are substantially horizontal so that the leg 58 can be pronged forwardly into a suitable opening in the rail 14. The coil spring 300 is preloaded, as indicated by the broken and solid line positions of the arm 440 so that the assembly 10c will function like the assembly 10. In some seating structures, a location of the spring strip 200 above the rear frame rail 14, as indicated in FIG. 5, is desirable for design purposes.

From the above description it is seen that this invention provides spring assemblies 10-10c, inclusive, in which a spring strip and a coil spring unit cooperate so that the coil spring unit effectively resists load applied to the spring strip over the full range of deflection of the spring assembly. This is readily accomplished in the assembly 10, for example, by extending the endmost torsion bar 24 in the spring strip 20 through the coil spring 30 and preloading the coil spring 30 so that it urges the arm 44 in a direction opposite to the direction of the loads applied to the spring strip 20. It is to be understood that while the invention has been particularly described with respect to mounting on front and rear frame rails, for illustrative purposes, it is also mountable on top and bottom rails to adapt it to back and similar spring situations.

It will be understood that the seat spring assembly utilizing auxiliary coil spring which is herein disclosed and described is presented for purposes of explanation and illustration and is not intended to indicate limits of the invention, the scope of which is defined by the following claims.

What is claimed is:

1. A spring assembly for seats comprising a longitudinally extending spring strip adapted to support a seating load directed substantially perpendicularly thereto on one side and terminating at one end in a transversely extending section, a coil spring having the coils therein extended about said section, mounting means for said assembly integral with one end of said coil spring, said mounting means including a first leg disposed closely adjacent said one coil end and extending substantially perpendicularly relative to said spring strip so as to be substantially parallel to said load direction so that saidload will have a minimum bending effect on said leg, and arm means integral with the opposite end of said coil spring extended longitudinally of said strip and engaged with the opposite side of said strip, said coil spring being preloaded so that said arm means exerts a force on said strip in a direction to resist said load and such that when said strip is subjected to said load said arm means is moved in a direction to tighten said coils.

2. A spring assembly according to claim 1 in which said mounting means also includes a second leg which constitutes a prong.

3. A spring assembly according to claim 1 in which said spring strip is formed of zigzag wire and has a pair of transversely extending torsion bars disposed adjacent said one end and spaced apart in a direction longitudinally of said strip, and said arm means engages said torsion bars so as to exert said force on said strip.

4. A spring assembly according to claim 2 in which the axis of said coil spring is substantially horizontal and said legs extend substantially vertically in a spaced apart relation in a direction longitudinally of said strip, and a short integral connecting section extending between the upper ends of said legs.

5. In a spring assembly, a coil spring unit comprising a wire body having an intermediate section formed into a plurality of coils having a horizontal axis, said body having one end section formed to substantially hook shape for mounting said body on a frame, said hook shape end section including a substantially vertical first leg extending perpendicular to said axis and located in a plane adjacent said coils and a second leg connected to said first leg and arranged in a substantially parallel relation therewith, the opposite end of said body being shaped to form an arm extending transversely of said axis so that said coils resiliently resist rotational movement of said end portions in opposite directions about said axis.

6. In a spring assembly, a coil spring unit having the structure according to claim 5 wherein said first leg is integral with and constitutes an extension of one of the endmost coils in said plurality of coils.

References Cited UNITED STATES PATENTS 2,250,486 7/ 1941 Krouheim 267-1 3,276,765 10/1966 Slominski et a1. ......l 267-1 12 ARTHUR L. LA POINT, Primary Examiner. 

1. A SPRING ASSEMBLY FOR SEATS COMPRISING A LONGITUDINALLY EXTENDING SPRING STRIP ADAPTED TO SUPPORT A SEATING LOAD DIRECTED SUBSTANTIALLY PERPENDICULARLY THERETO ON ONE SIDE AND TERMINATING AT ONE END IN A TRANSVERSELY EXTENDING SECTION, A COIL SPRING HAVING THE COILS THEREIN EXTENDED ABOUT SAID SECTION, MOUNTING MEANS FOR SAID ASSEMBLY INTEGRAL WITH ONE END OF SAID COIL SPRING, SAID MOUNTING MEANS INCLUDING A FIRST LEG DISPOSED CLOSELY ADJACENT SAID ONE COIL END AND EXTENDING SUBSTANTIALLY PERPENDICULARLY RELATIVE TO SAID SPRING STRIP SO AS TO BE SUBSTANTIALLY PARALLEL TO SAID LOAD DIRECTION SO THAT SAID LOAD WILL HAVE A MINIMUM BENDING EFFECT ON SAID LEG, AND ARM MEANS INTEGRAL WITH THE OPPOSITE END OF SAID COIL SPRING EXTENDED LONGITUDINALLY OF SAID STRIP AND ENGAGED WITH THE OPPOSITE SIDE OF SAID STRIP, SAID COIL SPRING BEING PRELOADED SO THAT SAID ARM MEANS EXERTS A FORCE ON SAID STRIP IN A DIRECTION TO RESIST SAID LOAD AND SUCH THAT WHEN SAID STRIP IS SUBJECTED TO SAID LOAD SAID ARM MEANS IS MOVED IN A DIRECTION TO TIGHTEN SAID COILS. 